@pierrebecerril@startupchile The Swift Summary Book is an interactive chapter-by-chapter summary of Apple's official documentation, built right into Playgrounds! You can tinker with it as much as you want!

@jnavon Thanks for your support. The book was written in Playgrounds, which means it offers a better reading experience for those with an OS X development environment.
Knowledge-wise, the target is broad. Anyone from devs transitioning from Obj-C to first-time Apple coders :)